Just picked a couple of these up in my Sainsbury's (Spalding) but they will be in any other Sainsbury's store with a pre-filled Paladone gift shipper - it's a tall cardboard display with 'Santa's Grotto' sign on top, with an assortment of gift items. I'd imagine most larger stores have them. Doesn't show up on the website. I've put it in the Gaming category on here because it seemed like the best fit :)
Design a new level or re-create a classic!
80 magnetic characters and icons from the original game
Mix and match to customize your fridge
Not suitable for children under 36 months
Officially licensed product
Look like a nice quality item, and obviously can be used on things other than fridges... Gets good reviews on Amazon and elsewhere and there's a few example pics kicking around the internet as well. Here's a link to the Amazon page :https://www.amazon.co.uk/Super-Mario-Bros-Magnets-Multi-Colour/dp/B01DDNB0K4/ref=sr_1_4?s=kitchen&ie=UTF8&qid=1480794672&sr=1-4&keywords=Super+Mario+Bros.
Sainsbury's SKU number for checking stock is 130830846
£4.99 on Amazon (dispatched by Amazon themselves but out of stock until 9th December) and seem to be around that price elsewhere. Looks like a good quality set and a good gift for geeky 31 year olds like myself that grew up with Mario, or younger players who are getting into it :D